The Subject Recruitment, Sample procurement, Retention, and Follow-up Core is designed to provide central access point to all participants for the coordination of patient sampling. The purpose of this Core is to insure adequate sample collection, while minimizing the confusion possible when multiple projects access the same patients. This central acquisition point will enable investigators to build on the information collected by the entire center by having centralized knowledge of sample availability. This Core will also minimize respondent burden because redundant questionnaires or information will be eliminated, repeated sampling eliminated, and possibly reduced the sampling necessary through creative sharing of samples. Basically, this Core is responsible for the collection of saliva and plaque samples for projects 1 & 2, cord blood at the time of delivery for project 3, saliva and breast milk for project 3, and blood samples for project 4. The Core will gather these samples and distribute to investigators in each core while keeping reserves in the core. The Core is also responsible for the collection of demographic, medical, obstetrical, dental, and nutritional data from study subjects.